| 1. |
- Ge, Yaxin, 1992, et al.
(författare)
-
Emission Characteristics of NOx and SO2 during the Combustion of Antibiotic Mycelial Residue
- 2022
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Ingår i: International Journal of Environmental Research and Public Health. - : MDPI AG. - 1661-7827 .- 1660-4601. ; 19:3
-
Tidskriftsartikel (refereegranskat)abstract
- The antibiotic mycelial residue (AMR) generated from cephalosporin C production is a haz-ardous organic waste, which is usually disposed of by landfilling that causes potential secondary environmental pollution. AMR combustion can be an effective method to treat AMR. In order to develop clean combustion technologies for safe disposal and energy recovery from various AMRs, the emission characteristics of NOx and SO2 from AMR combustion were studied experimentally in this work. It was found that the fuel-N is constituted by 85% protein nitrogen and 15% inorganic nitrogen, and the fuel-S by 78% inorganic sulfur and 22% organic sulfur. Nitrogen oxide emissions mainly occur at the volatile combustion stage when the temperature rises to 400◦C, while the primary sulfur oxide emission appears at the char combustion stage above 400◦C. Increasing the combustion temperature and airflow cause higher NOx emissions. High moisture content in AMR can significantly reduce the NOx emission by lowering the combustion temperature and generating more reducing gases such as CO. For the SO2 emission, the combustion temperature (700 to 900◦C), airflow and AMR water content do not seem to exhibit obvious effects. The presence of CaO significantly inhibits SO2 emission, especially for the SO2 produced during the AMR char combustion because of the good control effect on the direct emission of inorganic SO2. Employing air/fuel staging technologies in combination with in-situ desulfurization by calcium oxide/salts added in the combustor with operation temperatures lower than 900◦C should be a potential technology for the clean disposal of AMRs. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.
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| 2. |
- Cheng, W., et al.
(författare)
-
Effect of oxidative torrefaction on particulate matter emission from agricultural biomass pellet combustion in comparison with non-oxidative torrefaction
- 2022
-
Ingår i: Renewable energy. - : Elsevier BV. - 0960-1481 .- 1879-0682. ; 189, s. 39-51
-
Tidskriftsartikel (refereegranskat)abstract
- Torrefaction could improve the fuel properties and reduce the operating costs. However, the particulate matter (PM) emission behavior during the torrefied pellet combustion remains unknown. In this work, cotton stalk was torrefied at a temperature of 220–300 °C with a O2 concentration of 0–21%. The torrefied pellet was burned out and PM emission behavior was investigated using a Dekati low-pressure impactor. The results show that oxidative torrefaction leads to notable decreases of H/C and O/C ratios, which makes the fuel properties similar to coals. The heating value is significantly improved and sensitive to the torrefaction temperature. Both non-oxidative and oxidative torrefaction give rise to considerable increase in the yield of PM10. The main composition of PM1 changed from KCl to K2SO4 due to the substantial release of Cl during torrefaction. Meanwhile, Ca and K contents in PM1-10 are generally high, implying that the presence of oxygen can facilitate the transformation of alkali and alkaline-earth metals into coarse particles. The torrefaction temperature at around 260 °C with a low O2 concentration of 0–6% are the optimal torrefaction operation conditions to produce good quality torrefied cotton stalk pellet with respect to high heating value and low PM emission in later combustion application.
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| 3. |
- Ding, C., et al.
(författare)
-
The research on anaerobic digestion conditions of biomethanation using low-temperature pyrolysis oil
- 2021
-
Ingår i: Zhongguo Huanjing Kexue/China Environmental Science. - 1000-6923. ; 41:8, s. 3676-3683
-
Tidskriftsartikel (refereegranskat)abstract
- This article focused on the research of anaerobic digestion conditions using low-temperature pyrolysis oil, including the fresh inoculum acclimatization, the operation conditions of pyrolysis oil (PO) digestion and the influence of biomass pyrolysis parameters. The coupling process was studied by controlling different pyrolysis parameters and anaerobic digestion parameters. It can be concluded that the fresh sludge inoculum acclimatization can significantly improve the tolerance to the inhibitors contained in the PO, thus, the methane production from the PO digestion to a great degree. The mesophilic condition was favorable to the biooil biomethanation for the low POs under 4% as used in the experiment, whereas the thermophilic condition was favorable for the high PO concentration of 10%. Besides, more methane production can be given by 0.85mm biomass particle size, 300℃ pyrolysis temperature in the downstream step of PO digestion.
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| 4. |
- Ding, Mingyue, et al.
(författare)
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Enhancement of conversion from bio-syngas to higher alcohols fuels over K-promoted Cu-Fe bimodal pore catalysts
- 2017
-
Ingår i: Fuel processing technology. - : Elsevier BV. - 0378-3820 .- 1873-7188. ; 159, s. 436-441
-
Tidskriftsartikel (refereegranskat)abstract
- A novel K-promoted Cu-Fe bimodal derived catalyst was designed to optimize the catalytic activity and higher alcohols selectivity in higher alcohols synthesis (HAS). The characterization results indicated that the Cu-Fe bimodal derived catalyst presented the bimodal pore structures. The adding of K promoter increased the BET surface area and promoted the dispersion of Cu and Fe species in the bimodal pores without destroying the bimodal structure, whereas the excessive adding of potassium resulted in easily the aggregation of bimetal active species. Incorporation of moderate K content enhanced the reduction of Cu and Fe species and promoted the formation of active bimetal species for HAS, while the bimodal derived catalyst with excessive K content restrained the reduction of bimetal particles, decreasing the catalytic activity for higher alcohols synthesis. In addition, the gradual increasing of K content in the Cu-Fe bimodal derived catalyst strengthened the interaction of K and bimetal active species, which was combined with the “confinement effect” of bimodal pore structures, shifting product distribution towards C2 + OH.
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| 5. |
- Jiang, Bingyi, et al.
(författare)
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Low-Grade Syngas Biomethanation in Continuous Reactors with Respect to Gas–Liquid Mass Transfer and Reactor Start-Up Strategy
- 2023
-
Ingår i: Fermentation. - : MDPI AG. - 2311-5637. ; 9:1
-
Tidskriftsartikel (refereegranskat)abstract
- In order to utilize a wider range of low-grade syngas, the syngas biomethanation was studied in this work with respect to the gas–liquid mass transfer and the reactor start-up strategy. Two reactors, a continuous stirred tank (CSTR) and a bubble column with gas recirculation (BCR-C), were used in the experiment by feeding an artificial syngas of 20% H2, 50% CO, and 30% CO2 into the reactors at 55 °C. The results showed that the CH4 productivity was slightly increased by reducing the gas retention time (GRT), but was significantly improved by increasing the stirring speed in the CSTR and the gas circulation rate in the BCR-C. The best syngas biomethanation performance of the CSTR with a CH4 productivity of 22.20 mmol·Lr−1·day−1 and a yield of 49.01% was achieved at a GRT of 0.833 h and a stirring speed of 300 rpm, while for the BCR-C, the best performance with a CH4 productivity of 61.96 mmol·Lr−1·day−1 and a yield of 87.57% was achieved at a GRT of 0.625 h and a gas circulation rate of 40 L·Lr−1·h−1. The gas–liquid mass transfer capability provided by gas circulation is far superior to mechanical stirring, leading to a much better performance of low-grade syngas biomethanation in the BCR-C. Feeding H2/CO2 during the startup stage of the reactor can effectively stimulate the growth and metabolism of microorganisms, and create a better metabolic environment for subsequent low-grade syngas biomethanation. In addition, during the thermophilic biomethanation of syngas, Methanothermobacter is the dominant genus.
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| 6. |
- Zhang, Zhenwen, et al.
(författare)
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CO Biomethanation with Different Anaerobic Granular Sludges
- 2021
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Ingår i: Waste and Biomass Valorization. - : Springer Science and Business Media LLC. - 1877-2641 .- 1877-265X. ; 12:7, s. 3913-3925
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Tidskriftsartikel (refereegranskat)abstract
- Abstract: Biomethanation of the syngas from biomass gasification provides an alternative method for production of biofuel and chemicals. CO in syngas plays a key role in biomethanation of syngas, as it is both a substrate and an inhibitor of certain methanogenesis processes. In this study, CO biomethanation by using a mixture of N2 and CO as the gas substrate, was investigated with the help of 5 adapted anaerobic granular sludges under thermophilic and mesophilic conditions. The results show that CO biomethanation by the adapted inocula is omnipresent. The sludge from the juice plant has a methane yield more than 80% of the theoretical value both at 37 °C and 55 °C. Increasing the temperature from 37 °C to 55 °C has a slight effect on the final methane production, but can significantly increase the CO consumption rate and shorten the time for CO biomethanation. Graphic Abstract: [Figure not available: see fulltext.].
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| 7. |
- Zhang, Zhe, et al.
(författare)
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Inhibition of carbon steel corrosion in phase-change-materials solution by methionine and proline
- 2016
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Ingår i: Corrosion Science. - : Elsevier BV. - 0010-938X .- 1879-0496. ; 111, s. 675-689
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Tidskriftsartikel (refereegranskat)abstract
- Inhibition of the 1045 carbon steel corrosion by methionine and proline in PCMs solution have been investigated. Electrochemical measurements show that these inhibitors can protect steel against corrosion, with a maximal protection efficiency up to 95.0% by methionine/proline compound inhibitor at molar ratio equal to 5:3. All inhibitors act as anodic-type inhibitor. FESEM, EDS, XRD characterization indicates that the corrosion of steel starts from pitting corrosion of Cl− ion, and gradually evolves into a general corrosion. The NH4FePO4·nH2O, Fe2O3 are the main corrosion products. XPS study confirms that Met and Pro molecule can adsorb on steel surface and form inhibition films. The inhibition mechanism was further investigated through theoretical modeling studies.
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| 8. |
- Chansa, Oris, et al.
(författare)
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Behavior of alkali minerals in oxyfuel co-combustion of biomass and coal at elevated pressure
- 2021
-
Ingår i: Journal of Zhejiang University: Science A. - 1673-565X. ; 22:2, s. 116-129
-
Tidskriftsartikel (refereegranskat)abstract
- Combustion of biomass or coal is known to yield aerosols and condensed alkali minerals that affect boiler heat transfer performance. In this work, alkali behavior in the pressurized oxyfuel co-combustion of coal and biomass is predicted by thermodynamic and chemical kinetic calculations. Existence of solid minerals is evaluated by X-ray diffraction (XRD) analysis of ashes from pressure thermogravimetric combustion. Results indicate that a rise in pressure affects solid alkali minerals negligibly, but increases their contents in the liquid phase and decreases them in the gas phase, especially below 900 °C. Thus, less KCl will condense on the boiler heat transfer surfaces leading to reduced corrosion. Increasing the blend ratio of biomass to coal will raise the content of potassium-based minerals but reduce the sodium-based ones. The alkali-associated slagging in the boiler can be minimized by the synergistic effect of co-combustion of sulphur-rich coal and potassium-rich biomass, forming stable solid K2SO4 at typical fluidized bed combustion temperatures. Kinetics modelling based on reaction mechanisms shows that oxidation of SO2 to SO3 plays a major role in K2SO4 formation but that the contribution of this oxidation decreases with increase in pressure.
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| 9. |
- Chen, Xu, et al.
(författare)
-
Catalytic fast pyrolysis of biomass to produce furfural using heterogeneous catalysts
- 2017
-
Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier BV. - 0165-2370 .- 1873-250X. ; 127, s. 292-298
-
Tidskriftsartikel (refereegranskat)abstract
- Furfural is a valuable chemical, the production of furfural from renewable biomass resources becomes more attractive in recent years. In this study, biomass fast pyrolysis with heterogeneous catalysts (titanium compounds (TiN, TiO2 and TiOSO4) and metal nitrides (MoN, GaN and VN)) for furfural production was investigated experimentally by means of pyrolysis-gas chromatography/mass-spectrometry (Py-GC/MS). The measurement results indicated that TiN and GaN promoted the furfural compounds production notably mainly through direct decomposition of oligosaccharides. The formation of furfural was promoted when the amount of TiN was increased, and the yield of furfural formed was about 5.5 times the size of that from non-catalytic pyrolysis when TiN/cellulose mass ratio was 4. The furfural yield decreased when the pyrolysis residence time increased from 10 to 30 s, which suggests competitive reactions (formation of 1, 6-anhydro-beta.-D-glucopyranose) against the formation of furfural. TiN, as a catalyst for fast pyrolysis towards furfural production, can be well applied to agriculture biomass residues. Comparing three biomass residues: corncob, wheat straw and cotton stalk, corncob showed higher furfural yield due to the higher holocellulose content, while wheat straw showed higher furfural selectivity.
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| 10. |
- Cheng, W., et al.
(författare)
-
Mitigation of ultrafine particulate matter emission from agricultural biomass pellet combustion by the additive of phosphoric acid modified kaolin
- 2021
-
Ingår i: Renewable energy. - : Elsevier BV. - 0960-1481 .- 1879-0682. ; 172, s. 177-187
-
Tidskriftsartikel (refereegranskat)abstract
- The emission of ultrafine particulate matter (PM0.2) originated from the agricultural biomass pellet combustion poses great threat to atmospheric environment and human health, which restricts its large-scale utilization. In this study, a new phosphoric acid modification method is proposed to improve the PM0.2 reduction efficiency by kaolin additive. The effects of phosphoric acid concentration and treatment time on the physicochemical properties of kaolin and on the mitigation of PM0.2 emission from the pellet combustion are investigated. Results indicate that phosphoric acid modification destroy the internal structure of kaolin by the leaching of Al cations and the formation of active free silica. Meanwhile, the pore structure increases after modification with residual P deposited on the surface, which results in better alkali capture ability of modified kaolin. With the addition of phosphoric acid modified kaolin, significant reduction of PM0.2 emission can be achieved and the reduction ratio is proportional to the acid concentration. The maximum PM0.2 emission reduction ratio reaches 64.5% for the kaolin additive modified by 12 mol/L phosphoric acid for 6 hours. Finally, the PM0.2 reduction mechanism is proposed based on the analysis results, which provides technical knowhow for the industrial application of agricultural biomass pellet combustion.
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| 11. |
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| 12. |
- Fallahjoybari, Nima, et al.
(författare)
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A comparative study of different heat transfer enhancement mechanisms in a partially porous pipe
- 2021
-
Ingår i: SN Applied Sciences. - : Springer Science and Business Media LLC. - 2523-3963 .- 2523-3971. ; 3:10
-
Tidskriftsartikel (refereegranskat)abstract
- The effect of porous material position on the heat transfer inside a pipe working in a turbulent regime is studied here to obtain a detailed understanding of the heat transfer enchantment mechanisms in different porous substrate positions. To this end, an in-house Fortran code is developed to solve the governing equations using the finite volume method and SIMPLE algorithm. Turbulent flow in porous media is modeled using a modified version of k–ε model. The flow field and heat transfer inside the partially filled pipe are investigated for the two cases of central and boundary configurations. The porous and flow characteristics including Reynolds number, Darcy number, the conductivity ratios of solid to fluid and the thickness of inserted porous layer are varied and the heat transfer performance is studied in different cases. It is observed that two entirely different phenomena enhance the heat transfer in central and boundary configurations. While the channeling of fluid between the porous media and the pipe wall highly affects the heat transfer performance in the former, the thermal conductivity of porous media plays a highly critical role in the latter configuration. It is shown that, for the same filling ratio, inserting the porous layer at the core of the pipe is more effective than placing it at the wall. Investigating porous materials with different solid conductivities revealed that covering the pipe wall with a porous material is justified only for solid matrixes with high thermal conductivities.
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| 13. |
- Fatahian, Hossein, et al.
(författare)
-
Improving the flow uniformity in compact parallel-flow heat exchangers manifold using porous distributors
- 2022
-
Ingår i: Journal of thermal analysis and calorimetry (Print). - : Springer Science and Business Media LLC. - 1388-6150 .- 1588-2926. ; 147:22, s. 12919-12931
-
Tidskriftsartikel (refereegranskat)abstract
- The present study deals with the numerical simulation of turbulent flow in a Z-type manifold in which the fluid is distributed via nine distribution tubes. One of the major drawbacks of such devices is the mal-distribution of flow within these tubes. The flow rates are usually low in the first tubes close to the header entrance and increase in the other tubes. To address this problem and achieve a more uniform flow distribution inside the manifold, a novel solution is introduced in the present study, which includes the insertion of thin layers of porous media at the inlet of distribution tubes. In addition, a parametric study is conducted to evaluate the effect of porous media geometrical parameters such as pore diameter, porosity, and porous layer thickness on flow distributions among the tubes. The results demonstrate that the proposed approach increases the uniformity of flow distribution specifically when a porous media with higher resistance against the fluid flow is inserted uniformly within the manifold. In this case, a standard deviation as small as Phi=0.0067 could be reached showing the high level of flow uniformity within the manifold. Also, a maximum pressure drop of 12.557 kPa is observed which is approximately 38% larger than that calculated in the manifold without porous insertions. Moreover, several non-uniform distributions of porous media are also investigated to further improve the flow uniformity and decrease the pressure drop. An improvement in the standard deviation of Phi=0.0043 is obtained in the case of #E3 with a non-uniform porous distribution with a 5% reduction in pressure drop compared to the pressure drop calculated in the corresponding uniform case #E1. The results reveal the effectiveness of the approach presented here to reach a more uniform flow distribution within the manifold without the need for re-designing and altering the manifold geometry which is usually proposed in the literature.
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| 14. |
- Forsman, Björn, et al.
(författare)
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Alkali Metal Release During Rapid Pyrolysis of Fuel Blends Containing
- 2005
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Ingår i: Proceedings. 14th European conference and technology exhibition biomass for energy industry and climate protection, Paris, Oct. 2005.
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- In the present study the influence of different fuel blends and additives on the release of gaseous alkali metals during rapid pyrolysis of biomass has been investigated. A single particle reactor has been used together with a molecular beam mass spectrometer (MBMS) to study the release of gaseous alkali-containing emissions during pyrolysis. A hot platinum filament was used as the ionization source and alkali-containing compounds that hit the hot filament dissociate and alkali ions leave the Pt -filament and are detected in the MBMS. The fuels used were wood (spruce) and wood waste. The additives included peat, different sewage sludge samples, sludge from the pulp and paper industry and fly ash from co-combusted wood and sewage sludge. Experimental results show time resolved mass loss curves of biomass particles during rapid pyrolysis combined with released amounts of sodium (Na) and potassium (K). The results indicate that the new combined instrument successfully detects gaseous alkali metals, and a difference in the release of Na and K during pyrolysis due to the use of the additives is observed. Additives consisting of sewage sludge ash reduced the release of alkali, probably due to the presence of mullite in the ash together with the sorption effect of fine particles.
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| 15. |
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| 16. |
- Ge, Yaxin, 1992, et al.
(författare)
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Effect of fresh bed materials on alkali release and thermogravimetric behavior during straw gasification
- 2023
-
Ingår i: Fuel. - : Elsevier BV. - 0016-2361 .- 1873-7153. ; 336
-
Tidskriftsartikel (refereegranskat)abstract
- Alkali-associated problems are key issues for the efficient use of straw that is available as a major renewable energy resource worldwide. The effects of six bed materials commonly used in fluidized bed reactors on straw pyrolysis and char gasification were evaluated using online monitoring of alkali release and thermogravimetric analysis. Scanning electron microscopy with energy dispersive spectroscopy was used to determine the elemental composition of the char surface. In the straw pyrolysis stage, alkali release is reduced by the addition of dolomite and silica due to alkali adsorption on the bed materials, and enhanced by the addition of alumina because of its high sodium content. In the char gasification stage, silica, sea sand, olivine, and ilmenite reduce the char reactivity and alkali release, which is attributed to transfer of Si and Ti from the bed materials to the char and reaction with alkali to form stable and catalytically inactive compounds. Alumina also reduces the char conversion rate by transfer of Al to the char and formation of K-Al-Si and Ca-Al-Si compounds, while alkali release from the straw and alumina blend remains high due to the high Na content in alumina. Dolomite initially appears to increase the char gasification reactivity, but the results are affected by conversion of volatile matter that deposited on the dolomite in the straw pyrolysis stage. Dolomite also significantly increases the alkali release, which is attributed to Ca reactions with aluminosilicate compounds that allow potassium to remain in volatile form. Fresh bed materials are concluded to have significant effects on straw conversion depending on their chemical composition, and the results can contribute to the understanding required for efficient use of straw in commercial applications of biomass thermochemical conversion.
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| 17. |
- Ge, Yaxin, 1992, et al.
(författare)
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Impacts of fresh bed materials on alkali release and fuel conversion rate during wood pyrolysis and char gasification
- 2023
-
Ingår i: Fuel. - : Elsevier BV. - 0016-2361 .- 1873-7153. ; 353
-
Tidskriftsartikel (refereegranskat)abstract
- Bed materials provide efficient heat transfer and catalytic function in the thermochemical conversion of biomass, but their interactions with the fuel remain incompletely understood. In this study, the effects of bed materials on alkali release and fuel conversion during wood pyrolysis and CO2 gasification are investigated by online alkali detection combined with thermogravimetric analysis. The investigated bed materials include silica, sea sand, alumina and the natural ores olivine, ilmenite and dolomite. Only dolomite has a significant effect on fuel mass loss and alkali release during wood pyrolysis, while all bed materials influence char reactivity and alkali release during gasification. Sea sand, alumina and dolomite enhance the char gasification during the whole or most of the gasification process, which is related to alkali migration from the bed materials. All bed materials affect char reactivity and alkali release when the conversion approaches completion, and small amounts of some bed materials reduce the alkali release by an order of magnitude. The findings can be understood based on the chemical composition of the different materials. Silicon-rich materials reduce the levels of catalytically active alkali by formation of stable alkali silicates, and a similar explanation applies for ilmenite that captures alkali efficiently. Magnesium and calcium in contrast promote alkali release through their influence on alkali silicate chemistry. Analysis of char surfaces using scanning electron microscopy with energy dispersive spectroscopy indicates that low amounts of several elements are transferred from the bed material to the char where they may be directly involved in the char conversion process. The transferred elements are specific for each bed material and relates to their chemical composition. Mechanisms for material exchange between bed material and char are discussed.
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| 18. |
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| 19. |
- Göransson, Kristina, et al.
(författare)
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An experimental study on catalytic bed materials in a biomass dual fluidised bed gasifier
- 2015
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Ingår i: Renewable energy. - : Elsevier BV. - 0960-1481 .- 1879-0682. ; 81, s. 251-261
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Tidskriftsartikel (refereegranskat)abstract
- A study on in-bed material catalytic reforming of tar/CH4 has been performed in the 150 kW allothermal gasifier at Mid Sweden University (MIUN). The major challenge in biomass fluidised-bed gasification to produce high-quality syngas, is the reforming of tars and CH4. The MIUN gasifier has a unique design suitable for in-bed tar/CH4 catalytic reforming and continuously internal regeneration of the reactive bed material. This paper evaluates the catalytic effects of olivine and Fe-impregnated olivine (10%wtFe/olivine Catalyst) with reference to silica sand in the MIUN dual fluidised bed (DFB) gasifier. Furthermore, a comparative experimental test is carried out with the same operation condition and bed-materials when the gasifier is operated in the mode of single bubbling fluidised bed (BFB), in order to detect the internal regeneration of the catalytic bed materials in the DFB operation. The behaviour of catalytic and non-catalytic bed materials differs when they are used in the DFB and the BFB. Fe/olivine and olivine in the BFB mode give lower tar and CH4 content together with higher H-2 + CO concentration, and higher H-2/CO ratio, compared to DFB mode. It is hard to show a clear advantage of Fe/olivine over olivine regarding tar/CH4 catalytic reforming. (C) 2015 Elsevier Ltd. All rights reserved.
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| 20. |
- Göransson, Kristina, et al.
(författare)
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Biogas production from biological methanation of syngas
- 2018
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Ingår i: European Biomass Conference and Exhibition Proceedings. - : ETA-Florence Renewable Energies. ; , s. 512-515
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Konferensbidrag (refereegranskat)abstract
- Biogas to be used as gas vehicle fuel is a highly potential source to meet transport fuel demand and give a significant contribution to the Swedish target: vehicle fleet independent of fossil fuels by 2030. At present the biogas market is limited by the amount of available organic waste and the associated infrastructure. To overcome these issues, biomass could either be gasified into syngas and synthesized into bio-SNG (Synthetic Natural Gas) through catalytic methanation, or biomass gasification could be integrated into the biogas system to produce methane through biological methanation. Biomass gasification integrated in biological methanation is a relatively new idea and technology. Syngas conversion to methane by anaerobic cultures is practically unexplored, and few reports are available on this subject. Nevertheless, the pathway has been receiving intensive attractions and R&D recent years. For this purpose, a novel pathway by integrating biomass gasification into biogas system is studied in detail. This paper reviews the whole process from integration of biomass gasification into the biogas system to methane production through biological methanation: Biomass gasification > H2+CO > Biogas digester > Upgrading > Natural gas network.
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| 21. |
- Göransson, Kristina, et al.
(författare)
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BTL laboratory at Mid Sweden University
- 2008
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Ingår i: 16th European Biomass Conference. - Florence : Italy. ; , s. 1041-1045
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Konferensbidrag (refereegranskat)abstract
- This paper presents the BTL (biomass to liquids) laboratory of MIUN (Mid Sweden University) for production of bio-automotive fuels through biomass gasification. The process is intended to be realized in laboratory scale at MIUN with focus on key issues in the BTL technology development. Thus, the BTL laboratory becomes a resource for BTL education, research and development. The BTL laboratory is based on indirect gasification and the gasifier is a combination of a BFB steam gasifier and a CFB combustion riser. The biomass feeding system is unique in application. The syngas is automatically sampled and analyzed on-line on demand. Considering small & medium scale bio-automotive fuel plant, an oxygen plant would be too expensive to be integrated in BTL systems. An indirect gasifier is thus the choice for development to obtain a good quality high energy content synthesis gas. Based on calculation work performed by TPS, the most energy effective gasification technique is indirectly fluidized bed gasification with steam as the gasification agent. Integration of the gasifier and FT/DME/EtOH-reactors will be emphasized and a theoretic BTL model will be developed. The plan is to develop an effective and a reliable BTL technology under 100 MW possible for bio refinery integration.
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| 22. |
- Göransson, Kristina, et al.
(författare)
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CATALYTIC REDUCTION OF TAR/CH4 BY AN INTERNAL REFORMER IN A DFB GASIFIER
- 2014
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Ingår i: European Biomass Conference & Exhibition Proceedings. - 9788889407523 ; , s. 620-625
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- An internal reformer is developed for in-situ catalytic reforming of tar and methane (CH4) in allothermal gasifiers. Reduction of tars and CH4 in the syngas is a challenge for commercialization of biomass fluidised-bed gasification technology towards advanced automotive fuel production. This paper presents an initial study on the internal reformer operated with and without Ni-catalytic pellets in the Mid Sweden University (MIUN) DFB (Dual Fluidised Bed) gasifier, by evaluation of the syngas composition and tar/CH4 content. The novelty with the application of Ni-catalyst in this paper is the selected location where intensive gas to catalytic-material and bed-material contacts improve the reforming reactions. It can be concluded that the reformer with Ni-catalytic pellets clearly gives a higher H2 content together with lower CH4 and tar contents in the syngas than the reformer without Ni-catalytic pellets. The gravimetric tar content decreases down to 5 g/m3 and the CH4 content down below 6% in the syngas. The tar content will be decreased further to lower levels, with increased gas contact to the specific surface area of the catalyst and increased catalyst surface-to-volume ratio. The new design in the MIUN gasifier increases the gasification efficiency, suppresses the tar generation and upgrades the syngas quality.
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| 23. |
- Göransson, Kristina, et al.
(författare)
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Experimental test on a novel dual fluidised bed biomass gasifier for synthetic fuel production
- 2011
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Ingår i: Fuel. - : Elsevier BV. - 0016-2361 .- 1873-7153. ; 90:4, s. 1340-1349
-
Tidskriftsartikel (refereegranskat)abstract
- This article presents a preliminary test on the 150 kWth allothermal biomass gasifier at MIUN (Mid Sweden University) in Härnösand, Sweden. The MIUN gasifier is a combination of a fluidised bed gasifier and a CFB riser as a combustor with a design suitable for in-built tar/CH4 catalytic reforming. The test was carried out by two steps: 1) fluid-dynamic study; 2) measurements of gas composition and tar. A novel solid circulation measurement system which works at high bed temperatures is developed in the presented work. The results show the dependency of bed material circulation rate on the superficial gas velocity in the combustor, the bed material inventory and the aeration of solids flow between the bottoms of the gasifier and the combustor. A strong influence of circulation rate on the temperature difference between the combustor and the gasifier was identified. The syngas analysis showed that, as steam/biomass (S/B) ratio increases, CH4 content decreases and H2/CO ratio increases. Furthermore the total tar content decreases with increasing steam/biomass ratio and increasing temperature. The biomass gasification technology at MIUN is simple, cheap, reliable, and can obtain a syngas of high CO+H2concentration with sufficient high ratio of H2 to CO, which may be suitable for synthesis of Methane, DME, FT-fuels or alcohol fuels. The measurement results of MIUN gasifier have been compared with other gasifiers. The main differences can be observed in the H2 and the CO content, as well as the tar content. These can be explained by differences in the feed systems, operating temperature, S/B ratio or bed material catalytic effect etc..
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| 24. |
- Göransson, Kristina, et al.
(författare)
-
Internal tar/CH4 reforming in a biomass dual fluidised bed gasifier
- 2014
-
Ingår i: Proceeding of 4th International Symposium on Gasification and its Applications.
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- An internal reformer is developed for in-situ catalytic reforming of tar and methane (CH4) in allothermal gasifiers. The study has been performed in the 150 kW dual fluidised bed (DFB) biomass gasifier at Mid Sweden University (MIUN). The MIUN gasifier is built for research on synthetic fuel production. Reduction of tars and CH4 (except for methanation application) in the syngas is a major challenge for commercialization of biomass fluidised-bed gasification technology towards automotive fuel production. The MIUN gasifier has a unique design with an internal reformer, where intensive contact of gas and catalytic solids improves the reforming reactions. This paper presents a study on the internal reformer operated with and without Ni-catalytic pellets, by evaluation of the syngas composition and tar/CH4 content. It can be concluded that the reformer with Ni-catalytic pellets clearly gives a higher H2 content together with lower CH4 and tar contents in the syngas than the reformer without Ni-catalytic pellets. The gravimetric tar content decreases down to 5 g/m3 and the CH4 content down below 6% in the syngas. The novel design in the MIUN gasifier increases the gasification efficiency, suppresses the tar generation and upgrades the syngas quality
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| 25. |
- Göransson, Kristina
(författare)
-
Internal Tar/CH4 Reforming in Biomass Dual Fluidised Bed Gasifiers towards Fuel Synthesis
- 2014
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Production of high-quality syngas from biomass gasification in a dual fluidised bed gasifier (DFBG) has made a significant progress in R&D and Technology demonstration. An S&M scale bio-automotive fuel plant close to the feedstock resources is preferable as biomass feedstock is widely sparse and has relatively low density, low heating value and high moisture content. This requires simple, reliable and cost-effective production of clean and good syngas. Indirect DFBGs, with steam as the gasification agent, produce a syngas of high content H2 and CO with 12-20 MJ/mn3 heating value. The Mid Sweden University (MIUN) gasifier, built for research on synthetic fuel production, is a dual fluidised bed gasifier. Reforming of tars and CH4 (except for methanation application) in the syngas is a major challenge for commercialization of biomass fluidised-bed gasification technology towards automotive fuel production. A good syngas from DFBGs can be obtained by optimised design and operation of the gasifier, by the use of active catalytic bed material and internal reforming. This thesis presents a series of experimental tests with different operation parameters, reforming of tar and CH4 with catalytic bed material and reforming of tar and CH4 with catalytic internal reformer. The first test was carried out to evaluate the optimal operation and performance of the MIUN gasifier. The test provides basic information for temperature control in the combustor and the gasifier by the bed material circulation rate. After proven operation and performance of the MIUN gasifier, an experimental study on in-bed material catalytic reforming of tar/CH4 is performed to evaluate the catalytic effects of the olivine and Fe-impregnated olivine (10%wtFe/olivine Catalyst) bed materials, with reference to non-catalytic silica sand operated in the mode of dual fluidised beds (DFB). A comparative experimental test is then carried out with the same operation condition and bed-materials but when the gasifier was operated in the mode of single bubbling fluidised bed (BFB). The behaviour of catalytic and non-catalytic bed materials differs when they are used in the DFB and the BFB. Fe/olivine and olivine in the BFB mode give lower tar and CH4 content together with higher H2+CO concentration, and higher H2/CO ratio, compared to DFB mode. It is hard to show a clear advantage of Fe/olivine over olivine regarding tar/CH4 catalytic reforming. In order to significantly reduce the tar/CH4 contents, an internal reformer, referred to as the FreeRef reformer, is developed for in-situ catalytic reforming of tar and CH4 using Ni-catalyst in an environment of good gas-solids contact at high temperature. A study on the internal reformer filled with and without Ni-catalytic pellets was carried out by evaluation of the syngas composition and tar/CH4 content. It can be concluded that the reformer with Ni-catalytic pellets clearly gives a higher H2 content together with lower CH4 and tar contents in the syngas than the reformer without Ni-catalytic pellets. The gravimetric tar content decreases from 25 g/m3 down to 5 g/m3 and the CH4 content from 11% down below 6% in the syngas. The MIUN gasifier has a unique design suitable for in-bed tar/CH4 catalytic reforming and continuously internal regeneration of the reactive bed material. The novel design in the MIUN gasifier increases the gasification efficiency, suppresses the tar generation and upgrades the syngas composition.
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| 26. |
- Göransson, Kristina, et al.
(författare)
-
Internal Tar/CH4 Reforming using a Novel Design in a Biomass Dual Fluidised Bed Gasifier
- 2013
-
Ingår i: 21st European Biomass Conference and Exhibition. - Florence, Italy : ETA-Florence Renewable Energies. - 9788889407530 ; , s. 2038-2042
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Reforming of tars and methane (CH4) in syngas is a significant challenge for low-temperature biomass gasification. For a dual fluidised bed gasifier (DFBG), catalytic bed materials are usually used to promote the reforming reactions. Intensive contact between gas and catalytic bed material at high temperature enhances the internal tar/CH4 reforming. The MIUN gasifier, built for research into synthetic fuel production, is a dual fluidised bed gasifier (DFBG). The results with different bed materials (silica sand, olivine and Fe-impregnated olivine) give roughly equivalent amounts of methane and gravimetric tar in the raw untreated syngas, and need to be reduced to an acceptably low level. The gasification research group at MIUN investigates a novel design in the MIUN gasifier, to increase the gasification efficiency, suppress the tar generation and to upgrade the syngas quality. The first step is taken towards a novel design in the MIUN gasifier. The application is expected to significantly enhance the syngas quality.
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| 27. |
- Göransson, Kristina, et al.
(författare)
-
Internal tar/CH4 reforming in a biomass dual fluidised bed gasifier.
- 2015
-
Ingår i: Biomass Conversion and Biorefinery. - : Springer Science and Business Media LLC. - 2190-6815 .- 2190-6823. ; 5, s. 355-366
-
Tidskriftsartikel (refereegranskat)abstract
- An internal reformer is developed for in situ catalyticreforming of tar and methane (CH4) in allothermal gasifiers.The study has been performed in the 150 kW dual fluidised bed (DFB) biomass gasifier at Mid Sweden University(MIUN). The MIUN gasifier is built for research onsynthetic fuel production. Reduction of tars and CH4 (exceptfor methanation application) in the syngas is a major challengefor commercialization of biomass fluidised-bed gasificationtechnology towards automotive fuel production. The MIUN gasifier has a unique design with an internal reformer, where intensive contact of gas and catalytic solids improves the reforming reactions. This paper presents an initial study on the internal reformer operated with and without Ni-catalytic pellets, by evaluation of the syngas composition and tar/CH4 content. A novel application of Ni-catalyst in DFB gasifiers is proposed and studied in this work. It can be concluded that the reformer with Ni-catalytic pellets clearly gives a higher H2 content together with lower CH4 and tar contents in the syngas than the reformer without Ni-catalytic pellets. The gravimetric tar content decreases down to 5 g/m3 and the CH4 content down below 6 % in the syngas. The tar content can be decreased further to lower levels, with increased gas contact to the specific surface area of the catalyst and increased catalyst surface-to-volume ratio. The new design in the MIUN gasifier increases the gasification efficiency, suppresses the tar generation and upgrades the syngas quality.
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| 28. |
- Göransson, Kristina, et al.
(författare)
-
Preliminary Test on the Allothermal Gasifier at Mid Sweden University
- 2009
-
Ingår i: 17th European Biomass Conference. - Florence, Italy : ETA-Florence Renewable Energies.
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- This paper presents a preliminary test on the 150 kW allothermal biomass gasifier at MSU (Mid Sweden University) in Härnösand, Sweden. The MSU gasifier is a combination of a fluidized bed gasifier and a CFB riser as a combustor with an unique design suitable for in-built tar/CH4 catalytic reforming. The test was carried out by two steps, 1) fluid-dynamic study and 2) measurements of gas composition. The results show the dependency of bed material circulation rate on the superficial gas velocity in the combustor, the bed material inventory and the aeration of solids flow between the bottoms of the gasifier and the combustor. A strong influence of circulation rate on the temperature difference between the combustor and the gasifier was identified. The syngas analysis showed that, as steam/biomass ratio increases, CH4 content decreases and H2/CO ratio increases. The biomass gasification technology developed at MSU is simple, cheap, reliable, and can obtain a syngas of high CO+H2 concentration with sufficient high ratio of H2 to CO, suitable for synthesis of Methane, DME, FT-fuels or alcohol fuels This development work is expected to help for developing an effective and a reliable BTL technology in S&M scales under 200 MW, possibly for biorefinery integration.
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| 29. |
- Göransson, Kristina, et al.
(författare)
-
Review of syngas production via biomass DFBGs
- 2011
-
Ingår i: Renewable & sustainable energy reviews. - : Elsevier BV. - 1364-0321 .- 1879-0690. ; 15:1, s. 482-492
-
Forskningsöversikt (refereegranskat)abstract
- Production of high-quality syngas from biomass gasification in a dual fluidised bed gasifier (DFBG) has made a significant progress in R&D and Technology demonstration. An S&M scale bio-automotive fuel plant close to the feedstock resources is preferable as biomass feedstock is widely sparse and has relatively low density, low heating value and high moisture content. This requires a simple, reliable and cost-effective production of clean and good quality syngas. Indirect DFBGs, with steam as the gasification agent, produces a syngas of high content H2 and CO with 12-20 MJ/mn3 heating value. A good quality syngas from DFBGs can be obtained by optimised design and operation of the gasifier, by the use of active catalytic bed materials including internal reforming of tars and methane, and finally by a downstream cleaning process. This article reviews the whole process from gasification to high quality syngas. © 2010 Elsevier Ltd. All rights reserved.
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| 30. |
- Göransson, Kristina, et al.
(författare)
-
Tar/CH4 Reforming by Catalytic Bed Materials in a Biomass Fluidised Bed Gasifier
- 2012
-
Ingår i: 20th European Biomass Conference & Exhibition.
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- A study on in-bed catalytic material reforming of tar/methane (CH4) has been performed in the 150 kW allothermal biomass gasifier at Mid Sweden University (MIUN). The MIUN gasifier, built for research on synthetic fuel production, is a dual fluidised bed gasifier (DFBG). The syngas for automotive fuels synthesis has a strict specification of impurities. The biggest challenge for biomass fluidised-bed gasification is the reforming of tars and CH4. Internal reforming should be considered before downstream reforming. The MIUN gasifier has a unique design suitable for in-bed tar/CH4 catalytic reforming and continuously internal regeneration of the reactive bed material. The experimental tests are carried out in three cases: 1) basic condition with silica sand (no catalytic activity), 2) calcinated olivine, and 3) Fe-impregnated olivine (10%wtFe/Olivine Catalyst). The measurement results have been evaluated by comparing tar/CH4 content in the syngas from the gasifier operated under different operation conditions. These results in BFB mode have initiated the ongoing investigations of the catalytic effects and regeneration in DFB mode. It can be concluded that the Fe-impregnated olivine showed a surprising low reactivity for tar and CH4 reforming in the BFB model.
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| 31. |
- Göransson, Kristina, et al.
(författare)
-
TAR/CH4 REFORMING BY CATALYTICALLY ACTIVE MATERIALS IN A BIOMASS DUAL FLUIDISED BED GASIFIER
- 2010
-
Ingår i: The second International Symposium on Gasification and Its Application (ISGA 2010), December 5-8, Fukuoka, Japan.
-
Konferensbidrag (refereegranskat)abstract
- This paper presents a study on the effects of catalytically active materials, before tests in the 150 kW allothermal biomass gasifier at Mid Sweden University (MIUN). The gasifier has been built up in 2008 for research on synthetic fuel production, and is a combination of a circulating fluidised bed (CFB) riser as combustor and a fluidised bed (FB) as steam gasifier. The MIUN gasifier has a unique design suitable for in-built tar/methane (CH4) catalytic reforming. The lifetime of the catalyst can be prolonged using a dual fluidised bed gasifier (DFBG) with continuously internal regeneration of the catalyst. The catalytic effects of 1) basic condition with silica sand (no catalytic activity), 2) commercial catalyst, 3) development metal-catalyst (high surface area support), and 4) olivine catalyst will be evaluated by comparing tar/CH4 content in the syngas from the gasifier operated under different conditions. Silica sand and commercial catalyst can be considered as extremes for comparing the activity of the chosen conditions.
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| 32. |
- He, Jie, et al.
(författare)
-
Bio-SNG production in a TMP Mill in comparison with BIGCC
- 2014
-
Ingår i: Energy Procedia. - : Elsevier. - 1876-6102. ; , s. 2894-2897
-
Konferensbidrag (refereegranskat)abstract
- Biorefinery as a concept for polygeneration of various bio-based materials, fuels and chemicals has been more and more attractive. This concept is applied to the thermomechanical pulp (TMP) and paper industry in the present study to evaluate the possibility of co-production of substitute natural gas (SNG), electricity and district heating (DH) in addition to mechanical pulp and paper. In TMP mills, wood and biomass residues are commonly utilized for electricity and steam production through an associated combined heat and power (CHP) plant. This CHP plant is designed to be replaced by a biomass-T o-SNG (BtSNG) plant including an associated heat and power centre. Implementing BtSNG in a mechanical pulp production line might improve the profitability of a TMP mill and also help to commercialize the BtSNG technology by taking into account of some key issues such as, biomass availability, heat utilization etc. A TMP+BtSNG mathematical model is developed with ASPEN Plus.
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| 33. |
- He, Jie
(författare)
-
Gasification-based Biorefinery for Mechanical Pulp Mills
- 2014
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The modern concept of “biorefinery” is dominantly based on chemical pulp mills to create more value than cellulose pulp fibres, and energy from the dissolved lignins and hemicelluloses. This concept is characterized by the conversion of biomass into various bio-based products. It includes thermochemical processes such as gasification and fast pyrolysis. In thermo-mechanical pulp (TMP) mills, the feedstock available to the gasification-based biorefinery is significant, including logging residues, bark, fibre material rejects, bio-sludges and other available fuels such as peat, recycled wood and paper products. On the other hand, mechanical pulping processes consume a great amount of electricity, which may account for up to 40% of the total pulp production cost. The huge amount of purchased electricity can be compensated for by self-production of electricity from gasification, or the involved cost can be compensated for by extra revenue from bio-transport fuel production. This work is to study co-production of bio-automotive fuels, bio-power, and steam via gasification of the waste biomass streams in the context of the mechanical pulp industry. Ethanol and substitute natural gas (SNG) are chosen to be the bio-transport fuels in the study. The production processes of biomass-to-ethanol, SNG, together with heat and power, are simulated with Aspen Plus. Based on the model, the techno-economic analysis is made to evaluate the profitability of bio-transport fuel production when the process is integrated into a TMP mill.The mathematical modelling starts from biomass gasification. Dual fluidized bed gasifier (DFBG) is chosen for syngas production. From the model, the yield and composition of the syngas and the contents of tar and char can be calculated. The model has been evaluated against the experimental results measured on a 150KWth Mid Sweden University (MIUN) DFBG. As a reasonable result, the tar content in the syngas decreases with the gasification temperature and the steam to biomass (S/B) ratio. The biomass moisture content is a key parameter for a DFBG to be operated and maintained at a high gasification temperature. The model suggests that it is difficult to keep the gasification temperature above 850 ℃ when the biomass moisture content is higher than 15.0 wt.%. Thus, a certain amount of biomass or product gas needs to be added in the combustor to provide sufficient heat for biomass devolatilization and steam reforming.For ethanol production, a stand-alone thermo-chemical process is designed and simulated. The techno-economic assessment is made in terms of ethanol yield, synthesis selectivity, carbon and CO conversion efficiencies, and ethanol production cost. The calculated results show that major contributions to the production cost are from biomass feedstock and syngas cleaning. A biomass-to-ethanol plant should be built over 200 MW.In TMP mills, wood and biomass residues are commonly utilized for electricity and steam production through an associated CHP plant. This CHP plant is here designed to be replaced by a biomass-integrated gasification combined cycle (BIGCC) plant or a biomass-to-SNG (BtSNG) plant including an associated heat & power centre. Implementing BIGCC/BtSNG in a mechanical pulp production line might improve the profitability of a TMP mill and also help to commercialize the BIGCC/BtSNG technologies by taking into account of some key issues such as, biomass availability, heat utilization etc.. In this work, the mathematical models of TMP+BIGCC and TMP+BtSNG are respectively built up to study three cases: 1) scaling of the TMP+BtSNG mill (or adding more forest biomass logging residues in the gasifier for TMP+BIGCC); 2) adding the reject fibres in the gasifier; 3) decreasing the TMP SEC by up to 50%.The profitability from the TMP+BtSNG mill is analyzed in comparison with the TMP+BIGCC mill. As a major conclusion, the scale of the TMP+BIGCC/BtSNG mill, the prices of electricity and SNG are three strong factors for the implementation of BIGCC/BtSNG in a TMP mill. A BtSNG plant associated to a TMP mill should be built in a scale above 100 MW in biomass thermal input. Comparing to the case of TMP+BIGCC, the NR and IRR of TMP+BtSNG are much lower. Political instruments to support commercialization of bio-transport fuel are necessary.
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| 34. |
- He, Jie, 1979-
(författare)
-
GASIFICATION-BASED BIOREFINERY FOR MECHANICAL PULP MILLS
- 2012
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The modern concept of "biorefinery" is dominantly based on chemical pulp mills to create more value than cellulose pulp fibres, and energy from the dissolved lignins and hemicelluloses. This concept is characterized by the conversion of biomass into various biobased products. It includes thermochemical processes such as gasification and fast pyrolysis. In mechanical pulp mills, the feedstock available to the gasification-based biorefinery is significant, including logging residues, bark, fibre material rejects, biosludges and other available fuels such as peat, recycled wood, and paper products. This work is to study co-production of bio-automotive fuels, biopower, and steam via gasification in the context of the mechanical pulp industry. Biomass gasification with steam in a dual-fluidized bed gasifier (DFBG) was simulated with ASPEN Plus. From the model, the yield and composition of the syngas and the contents of tar and char can be calculated. The model has been evaluated against the experimental results measured on a 150 KWth Mid Sweden University (MIUN) DFBG. The model predicts that the content of char transferred from the gasifier to the combustor decreases from 22.5 wt.% of the dry and ash-free biomass at gasification temperature 750 ℃ to 11.5 wt.% at 950 ℃, but is insensitive to the mass ratio of steam to biomass (S/B). The H2 concentration is higher than that of CO under normal DFBG operating conditions, but they will change positions when the gasification temperature is too high above about 950 ℃, or the S/B ratio is too far below about 0.15. The biomass moisture content is a key parameter for a DFBG to be operated and maintained at a high gasification temperature. The model suggests that it is difficult to keep the gasification temperature above 850 ℃ when the biomass moisture content is higher than 15.0 wt.%. Thus, a certain amount of biomass needs to be added in the combustor to provide sufficient heat for biomass devolatilization and steam reforming. Tar content in the syngas can also be predicted from the model, which shows a decreasing trend of the tar with the gasification temperature and the S/B ratio. The tar content in the syngas decreases significantly with gasification residence time which is a key parameter. Mechanical pulping processes, as Thermomechanical pulp (TMP), Groundwood (SGW and PGW), and Chemithermomechanical pulp (CTMP) processes have very high wood-to-pulp yields. Producing pulp products by means of these processes is a prerequisite for the production of printing paper and paperboard products due especially to their important functional properties such as printability and stiffness. However, mechanical pulping processes consume a great amount of electricity, which may account for up to 40% of the total pulp production cost. In mechanical pulping mills, wood (biomass) residues are commonly utilized for electricity production through an associated combined heat and power (CHP) plant. This techno-economic evaluation deals with the possibility of utilizing a biomass integrated gasification combined cycle (BIGCC) plant in place of the CHP plant. Integration of a BIGCC plant into a mechanical pulp production line might greatly improve the overall energy efficiency and cost-effectiveness, especially when the flow of biomass (such as branches and tree tops) from the forest is increased. When the fibre material that negatively affects pulp properties is utilized as a bioenergy resource, the overall efficiency of the system is further improved. A TMP+BIGCC mathematic model is developed based on ASPEN Plus. By means of this model, three cases are studied: 1) adding more forest biomass logging residues in the gasifier,2) adding a reject fraction of low quality pulp fibers to the gasifier, and3) decreasing the TMP-specific electricity consumption (SEC) by up to 50%. For the TMP+BIGCC mill, the energy supply and consumption are analyzed in comparison with a TMP+CHP mill. The production profit and the internal rate of return (IRR) are calculated. The results quantify the economic benefit from the TMP+BIGCC mill. Bio-ethanol has received considerable attention as a basic chemical and fuel additive. It is currently produced from sugar/starch materials, but can also be produced from lignocellulosic biomass via a hydrolysis--fermentation or thermo-chemical route. In terms of the thermo-chemical route, a few pilot plants ranging from 0.3 to 67 MW have been built and operated for alcohols synthesis. However, commercial success has not been achieved. In order to realize cost-competitive commercial ethanol production from lignocellulosic biomass through a thermo-chemical pathway, a techno-economic analysis needs to be done. In this work, a thermo-chemical process is designed, simulated, and optimized mainly with ASPEN Plus. The techno-economic assessment is made in terms of ethanol yield, synthesis selectivity, carbon and CO conversion efficiencies, and ethanol production cost. Calculated results show that major contributions to the production cost are from biomass feedstock and syngas cleaning. A biomass-to-ethanol plant should be built at around 200 MW. Cost-competitive ethanol production can be realized with efficient equipments, optimized operation, cost-effective syngas cleaning technology, inexpensive raw material with low pretreatment cost, high-performance catalysts, off-gas and methanol recycling, optimal systematic configuration and heat integration, and a high-value byproduct.
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| 35. |
- He, J H, et al.
(författare)
-
Research progress on biomass fuel ethanol
-
Annan publikation (populärvet., debatt m.m.)abstract
- Advances of domestic and overseas biomass fuel ethanol is outlined in this paper. Having evaluated its economic, energy, environmental and social benefits, thereafter its importance as a part of Chinese energy strategy had been confirmed. Finally, a feasible scheme for fuel ethanol production from biomass in large scale is suggested, used for reference.
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| 36. |
- He, Jie, et al.
(författare)
-
Research on ethanol synthesis from syngas
- 2008
-
Ingår i: Journal of Zhejiang University - Science A. - 1673-565X. ; 9:5, s. 714-719
-
Tidskriftsartikel (refereegranskat)abstract
- It is a very fine substitutable energy technology to synthesize ethanol from biomass-derived syngas. This paper summarized the development of preparing ethanol from syngas, and especially elaborated on the research status of catalysts for the process. Based on the relative researches on the reaction mechanism, structure and performance of the catalysts, the optimumdesign of catalysts with high activity was presented in this review, which set the theoretical and application foundation for the industrial production of ethanol from syngas.
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| 37. |
|
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| 38. |
- He, Jie, et al.
(författare)
-
Techno-economic evaluation of a mechanical pulp mill with gasification
- 2013
-
Ingår i: Nordic Pulp & Paper Research Journal. - 0283-2631 .- 2000-0669. ; 28:3, s. 349-357
-
Tidskriftsartikel (refereegranskat)abstract
- Mechanical pulping processes, including thermomechanical pulp (TMP), groundwood (SGW andPGW), and chemithermomechanical pulp (CTMP) processes, each have a very high wood-to-pulp yield. Producing pulp by means of these processes is a prerequisite for paper (such as printing paper and paperboard) grades requiring high printability and stiffness. However, mechanical pulping processes consume a great amount of electricity, which may account for up to 40% of the total pulp production cost.In mechanical pulping mills, wood (biomass) residues are commonly utilized for electricity production through an associated combined heat and power (CHP) plant. This techno-economic evaluation deals with the possibility of utilizing a biomass integrated gasification combined cycle (BIGCC) plant in place of the CHP plant.Implementing BIGCC in a mechanical pulp production line might greatly improve the overall energy efficiency and cost-effectiveness, especially when more biomass from forest (such as branches and tree tops) is available. When the fibre material that negatively affects pulp properties is utilized as a bioenergy resource, the overall efficiency will be further improved. A TMP+BIGCC mathematical model is developed with ASPEN Plus. By means of modeling, three cases are studied:1) adding more forest biomass logging residues in the gasifier,2) adding the reject fibres in the gasifier, and3) decreasing the TMP-specific electricity consumption (SEC) by up to 50%.For a TMP+BIGCC mill, the energy supply and consumption are analyzed in comparison with a TMP+CHP mill. The production profits are evaluated.
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| 39. |
- He, Jie, et al.
(författare)
-
Techno-economic evaluation of thermo-chemical biomass-to-ethanol
- 2011
-
Ingår i: Applied Energy. - : Elsevier BV. - 0306-2619 .- 1872-9118. ; 88:4, s. 1224-1232
-
Tidskriftsartikel (refereegranskat)abstract
- Bio-ethanol has received considerable attention as a basic chemical and fuel additive. Bio-ethanol is presently produced from sugar/starch materials, but can also be produced from lignocellulosic biomass via hydrolysis-fermentation route or thermo-chemical route. In terms of thermo-chemical route, a few pilot plants ranging from 0.3 to 67 MW have been built and operated for alcohols synthesis. However, commercial success has not been found. In order to realize cost-competitive commercial ethanol production from lignocellulosic biomass through thermo-chemical pathway, a techno-economic analysis needs to be done. In this paper, a thermo-chemical process is designed, simulated and optimized mainly with ASPEN Plus. The techno-economic assessment is made in terms of ethanol yield, synthesis selectivity, carbon and CO conversion efficiencies, and ethanol production cost. Calculated results show that major contributions to the production cost are from biomass feedstock and syngas cleaning. A biomass-to-ethanol plant should be built around 200 MW. Cost-competitive ethanol production can be realized with efficient equipments, optimized operation, cost-effective syngas cleaning technology, inexpensive raw material with low pretreatment cost, high performance catalysts, off-gas and methanol recycling, optimal systematic configuration and heat integration, and high value byproduct.
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| 40. |
- He, Qiao, et al.
(författare)
-
A study on latent heat storage exchangers with the high-temperature phase-change material
- 2001
-
Ingår i: International Journal of Energy Research. - : Hindawi Limited. - 0363-907X .- 1099-114X. ; 25:4, s. 331-341
-
Tidskriftsartikel (refereegranskat)abstract
- This paper presents a theoretical analysis and an experimental test on a shell-and-tube latent heat storage exchanger. The heat exchanger is used to recover high temperature waste heat from industrial furnaces and off-peak electricity. It can also be integrated into a renewable energy system as an energy storage component. A mathematical model describing the unsteady freezing problem coupled with forced convection is solved numerically to predict the performance of the heat exchanger. It provides a basis for optimum design of the heat exchanger. The experimental study on the heat exchanger is carried out under various operating conditions. Effects of various parameters, such as the inlet temperature, the mass flow rate, the thickness of the phase change material and the length of the pipes, on the heat transfer performance of the unit are discussed by combining with theoretical prediction. Criterion for analyzing and evaluating the performance of heat exchanger is also proposed.
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| 41. |
- Henschel, Till, et al.
(författare)
-
A study on the pyrolysis behaviour of different biomass fuels using thermogravimetry and online gas analysis
- 2016
-
Ingår i: European Biomass Conference and Exhibition Proceedings. - : ETA-Florence Renewable Energies. ; , s. 1290-1293
-
Konferensbidrag (refereegranskat)abstract
- Fuel availability and flexibility are important issues for biomass-based heat/power and advanced biofuel plants. The physical and chemical properties of biomass feedstocks vary from one to others to a great degree, which must be taken care of for the reactor design/operation, system optimization and blend feedstock application. In this work, the biomass property is evaluated based on pyrolysis behavior of biomass fuels by means of TGA and online gas analysis. Wood, pine bark, peat, straw, black liquor and microalgae are chosen as the biomass feedstocks for the pyrolysis study. The measurement results show high volatile content for algae and black liquor (around 85%) and low volatile content for pine bark and peat (around 69%). Differently from woody biomass, the DTG curve of straw has a single dominant peak at much lower temperature, which suggests a dominant component of hemicellulose in biomass, while algae and peat have a broader temperature specturm of devolatilization but much lower peak temperature. CO2 is released first and H2 later in the pyrolysis process for all biomass feedstocks, whileas the peak of CO formation follows CO2 formation trend for most feedstocks used, except for peat and pine bark which give a peak later at high temperature. This indicates secondary reactions of tar cracking, steam reforming and char gasification.
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| 42. |
- Hu, Junhao, et al.
(författare)
-
Co-gasification of coal and biomass : Synergy, characterization and reactivity of the residual char
- 2017
-
Ingår i: Bioresource Technology. - : Elsevier BV. - 0960-8524 .- 1873-2976. ; 244, s. 1-7
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Tidskriftsartikel (refereegranskat)abstract
- The synergy effect between coal and biomass in their co-gasification was studied in a vertical fixed bed reactor, and the physic-chemical structural characteristics and gasification reactivity of the residual char obtained from co-gasification were also investigated. The results shows that, conversion of the residual char and tar into gas is enhanced due to the synergy effect between coal and biomass. The physical structure of residual char shows more pore on coal char when more biomass is added in the co-gasification. The migration of inorganic elements between coal and biomass was found, the formation and competitive role of K2SiO3, KAlSiO4, and Ca3Al2(SiO4)(3) is a mechanism behind the synergy. The graphization degree is enhanced but size of graphite crystallite in the residual char decreases with biomass blending ratio increasing. TGA results strongly suggest the big difference in the reactivity of chars derived from coal and biomass in spite of influence from co-gasification.
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| 43. |
- Hu, Xiao, et al.
(författare)
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Product gas biomethanation with inoculum enrichment and grinding
- 2024
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Ingår i: Biomass Conversion and Biorefinery. - : Springer Nature. - 2190-6815 .- 2190-6823. ; 14:12, s. 12993-13004
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Tidskriftsartikel (refereegranskat)abstract
- The use of cheap product gas from biomass air gasification to produce methane via anaerobic digestion is a novel and potential pathway for the large-scale production of biomass-based substitute natural gas (BioSNG). In this experimental work, the product gas biomethanation (PGB) was studied with respect to the biosludge enrichment and inoculum partial grinding as well as the mesophilic and thermophilic conditions. The results show that the biosludge enrichment can effectively stop methanogenesis inhibition from the product gas, particularly CO, thus increase the biomethanation reaction rate and shorten the reaction start-up time. The inoculum partial grinding treatment can clearly change the microorganism composition and effectively reduce the diversity of microorganisms in the mixed bacterium system for the mesophilic biomethanation, thereby improving the product gas biomethanation efficiency, which is limited for the thermophilic biomethanation.
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| 44. |
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| 45. |
- Jiang, Bingyi, et al.
(författare)
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A novel approach to enhance CO biomethanation by semi-disaggregation of anaerobic granular sludge
- 2023
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Ingår i: Energy Conversion and Management. - : Elsevier BV. - 0196-8904 .- 1879-2227. ; 276
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Tidskriftsartikel (refereegranskat)abstract
- The syngas produced from biomass gasification is a great potential energy resource, which can well be utilized to produce biomass-based substitute natural gas (BioSNG) via syngas biomethanation. CO biomethanation is one of the key issues in the biomethanation process and was studied experimentally in this work with respect to the effect of anaerobic granular sludge semi-disaggregation. The results show 1.07 times higher averaged CH4 production rate with the semi-disaggregated granular sludge than the whole granular sludge at 35 °C, and 1.69 times higher at 55 °C. The main mechanisms behind the enhanced CH4 production rate, especially under the thermophilic condition, are the improvement of microbial interspecific syntrophic association caused by the higher electron and substrate transfer rate, and more active cell growth and metabolism as reflected in higher abundance of functional genes and enzymes and less useless extracellular polymeric substances. The CO biomethanation enhancement occurs in the conversion of the substrate to the intermediate products. The semi-disaggregation of anaerobic granular sludge or similar way to strengthen interspecific association is an effective approach to improve the ability and tolerance of microbial cultures under the CO atmosphere. This technique can well be applied for the energy conversion from the CO-rich gas substrates into BioSNG via CO biomethanation under the thermophilic condition, or for the production of intermediates as fuels/chemicals under the mesophilic condition.
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| 46. |
- Jiang, Bingyi, et al.
(författare)
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Evaluation of nano-scaled zero valent iron (nZVI) effects on continuous syngas biomethanation under the thermophilic condition
- 2023
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Ingår i: Chemical Engineering Journal. - : Elsevier. - 1385-8947 .- 1873-3212. ; 470
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Tidskriftsartikel (refereegranskat)abstract
- The nano-scaled zero valent iron (nZVI) particles were applied to strengthen the syngas biomethanation under the thermophilic condition in a continuous bubble column reactor with gas circulation. The CH4 productivity was increased by 6.80% from 71.20 mmol & BULL;Lr 1 & BULL;day 1 to the highest 76.04 mmol & BULL;Lr 1 & BULL;day 1 at the nZVI concen-tration of 2.5 g/L. The measurement of iron concentration and the observation of the iron nanoparticles dis-tribution indicate that nZVI can act as an electron conduit to enhance more efficient direct interspecies electron transfer by physically close contact between microorganisms, instead of biological corrosion. Further analysis of metabolic products shows that the nZVI addition can stimulate the EPS secretion, and the direct electron transfer relying on nZVI particles tends to replace other transfer modes. Microbial community analysis reveals that the Bacteria Bacteroidia and Firmicutes, and Archaea Methanothermobacter are the potential dominating enriched syntrophic partners. The expression of functional genes involved in methane production was also found to in-crease. On the other hand, the nZVI accumulation can lead to the albefaction and inactivation of partial sludge granules due to its toxicity. The negative effects of nZVI at high concentration are also more pronounced. This work shows the feasibility of improving continuous syngas biomethanation by strengthening interspecific as-sociation and accelerating electron transfer.
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| 47. |
- Jiang, Bingyi, et al.
(författare)
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Identification of the biomethanation pathways during biological CO2 fixation with exogenous H2 addition
- 2022
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Ingår i: Fuel processing technology. - : Elsevier BV. - 0378-3820 .- 1873-7188. ; 238
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Tidskriftsartikel (refereegranskat)abstract
- Power-to-gas allows conversion of surplus electricity to methane when CO2 is available, which becomes an important technology for carbon capture, utilization and sequestration, as well as for increasing the flexibility of electricity production from renewable energy resources such as wind and solar energy. H2/CO2 biomethanation is a potentially promising alternative to the conversion of H2/CO2 to methane without limitation of variable hydrogen production. To identify mixed culture-based metabolic pathways of H2/CO2 under the mesophilic (35 °C) and thermophilic (55 °C) conditions, two specific inhibitors, 2-bromoethane sulfonate (BES) and vancomycin were employed in this experimental study. The combination of hydrogenotrophic and homoacetogenesis-acetoclastic methanogenesis makes up the pathway for the mesophilic cultivated microbial consortia. 16S rRNA gene analysis indicates that abundant Bacteria, Methanobacterium and Methanosaeta play important role in the conversion. Further analysis shows close collaboration between microorganisms by the formation of microbial clustering and the production of humic acids. The detailed metabolic mechanisms further confirm a diverse biomethanation network under the mesophilic condition. While under the thermophilic condition, the H2/CO2 biomethanation is fully dominated by the direct hydrogenotrophic methanogenesis mainly with Methanothermobacter, which is straightforward but more efficient.
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| 48. |
- Jiang, X., et al.
(författare)
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Research on biogas production potential of aquatic plants
- 2014
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Ingår i: Renewable energy. - : Elsevier BV. - 0960-1481 .- 1879-0682. ; 69, s. 97-102
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Tidskriftsartikel (refereegranskat)abstract
- This paper is to explore the biogas production potential of wetland aquatic biomass plants. 7 species of wetland aquatic biomass plants are used in the study, which include 4 plants with more fiber carbohydrate, Acorus calamus Linn, Typha orientalis Presl, Pontederia cordata and Canna indica, and 3 plants with more starch carbohydrate, Colocasia tonoimo Nakai, Thalia dealbata and Hydrocotyle vulgaris. In the experiment, these plants were treated by anaerobic fermentation in batch mode at 37°C. The results show that the anaerobic biogas production potential (ABP, mL·g-1VS) of aquatic biomass plants is different for different components content (%TS). The correlation between ABP and hemicellulose content is significant and negative (R=-0.784, 0.01<p<0.05), and the correlation between ABP and starch carbohydrate content is significant and positive (R=0.767, 0.01<p<0.05). The multiple stepwise regression equation with cross variable can roughly meet the statistical model to reflect the coeffect of hemicellulose, cellulose, starch carbohydrate and lignin on ABP of aquatic biomass plants, y=238.62+2.60x1+28.55x2-2.08x2x3+12.67x3, (Adj-R2=0.962, p(intercept)=0.034, p(x1)=0.101, p(x2)=0.036, p(x2x3)=0.066, p(x3)=0.031, p=0.025, SD=9.95), y represents ABP (mLg-1VS), x1, x2 and x3 represents the cellulose, lignin and starch carbohydrate content (%TS) respectively.
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| 49. |
- Johnsson, Filip, 1960, et al.
(författare)
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Characteristics of the formation of particle wall-layers in CFB boilers
- 1995
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Ingår i: Proc of the 2nd International Conference on Multiphase Flow. ; 3, s. FB1-25-FB1-32-
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Konferensbidrag (refereegranskat)abstract
- The character of the vertical two-phase flow in circulating fluidized bed (CFB)boiler furnaces is compared with results from small CFB risers presented in literature. The particle flow in furnaces as well as in the smaller risers shows a core/wall-layer structure. In the CFB boilers the particle flow pattern develops up through the furnace with the major back-flow caused by separation to the furnace walls. Both the particle wall-layer thickness and the downward flux within this layer increase downwards along the furnace walls. In the smaller units this downward increase is either absent or much smaller, a consequence of a more developed particle flow profile, which, typically, is parabolic in shape.
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| 50. |
- Johnsson, Filip, 1960, et al.
(författare)
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Optical and momentum probe measurements in a CFB boiler
- 1996
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Ingår i: Proc of the 5th International Conference on Circulating Fluidized Bed. ; , s. 652-657
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Konferensbidrag (refereegranskat)abstract
- Methods for the characterization of the two-phase flow in the transport zone of circulating fluidized bed (CFB) boilers are discussed based on measurements of fluctuations in local solids concentration and momentum flux using an optimum probe and a momentum probe. Both probes were designed to withstand the environment inside a furnace during combustion. The dynamic information on the flow obtained by the two probes was in agreement. The time-resolved measurements in the core region as well as in the wall layer by continuous increases and decreases in solids concentration and momentum flow from a base level at low solids concentration.
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